One method for mounting a semiconductor chip on another semiconductor chip is flip chip mounting, in which solder bumps are formed on electrodes of one semiconductor chip and the bumps are connected to electrodes of the other semiconductor chip.
In the flip chip mounting, after the one semiconductor chip is mounted on the other semiconductor chip, a liquid underfill resin is injected between the semiconductor chips. Thereafter, the liquid underfill resin is heated and hardened. The hardened underfill resin protects joint parts between the semiconductor chips. (For example, refer to Japanese National Publication of International Patent Application WO2005/076352.)